Chest
Volume 106, Issue 3, September 1994, Pages 731-737
Journal home page for Chest

Clinical Investigations: Esophagus
Gastroesophageal Reflux-induced Bronchoconstriction: An Intraesophageal Acid Infusion Study Using State-of-the-Art Technology

https://doi.org/10.1378/chest.106.3.731Get rights and content

Study objective

To study mechanisms of gastroesophageal reflux-induced bronchoconstriction during intraesophageal infusions.

Design

Prospective study blinded to the subject.

Setting

Outpatient pulmonary function laboratory at a 908-bed university hospital.

Participants

Forty-seven adult subjects divided into four groups: asthmatics with reflux, 20; asthmatics, 7; gastroesophageal refluxers, 10; and normal controls, 10. Asthmatics were defined by American Thoracic Society criteria, and refluxers were defined by symptoms and 24-hour pH monitoring.

Interventions

Dual antimony esophageal pH probe placed just below the upper esophageal sphincter and 5 cm above the lower esophageal sphincter. Intraesophageal infusions of normal saline solution followed by 0.1N hydrochloric acid then normal saline solution were given for 15 to 18 min. Spirometry and specific airway resistance (SRaw) were performed after placement of pH probes, insertion of esophageal infusion tube, and after each infusion. Bernstein tests were assessed during esophageal infusions.

Measurements and results

Peak expiratory flow rate (PEF) decreased with intraesophageal acid in all four groups (p<0.014). Esophageal acid clearance improved PEF in all groups except the asthmatics with reflux group that had a further decrease in PEF. These effects were not dependent on a positive Bernstein test or evidence of proximal reflux. The asthmatics with reflux group also had an increase in SRaw with intraesophageal acid, which continued to increase despite acid clearance.

Conclusions

Intraesophageal acid infusions caused a decrease in PEF in all groups without evidence of microaspiration, implying a vagally mediated reflex may be involved. Esophageal mucosal inflammation, assessed by a positive Bernstein test, was not required. Asthmatics with reflux also had further decline in PEF despite acid clearance.

Section snippets

Subjects

Forty-seven adult subjects participated in this prospective study approved by the Human Use Committee at the University of Alabama at Birmingham on March 14,1990. Four groups were studied: (1) asthmatics with gastroesophageal reflux disease (AR), 20 patients; (2) asthmatics without gastroesophageal reflux disease (A), 7 patients; (3) gastroesophageal reflux disease only (R), 10 patients; and (4) normal controls (NC), 10 patients. All patients had a thorough history, baseline pulmonary function

Demographics of Patient Groups

Twenty patients with asthma and gastroesophageal reflux (AR) participated. The mean age was 43.3 years. The mean length of asthma symptoms was 13.5 years (range, 1 to 32 years). Seventy percent had nocturnal asthma symptoms, and 10 percent were smokers at one point in time. All patients were receiving β2-agonists, 40 percent were receiving prednisone, 35 percent were receiving inhaled steroids, 20 percent were receiving inhaled cromolyn sodium, 30 percent were receiving inhaled ipratropium

Pulmonary Function Response to Esophageal Acid Infusion

Baseline pulmonary spirometry and airway resistance were performed prior to intraesophageal infusions. There was no significant difference in the PFTs measured before feeding tube placement and those measured after tube placement. Therefore, PFTs performed after feeding tube placement were used as the baseline values in subsequent analyses.

Figure 2 shows the results of the ANCOVA for PEF. There was a significant main effect of subject group (p<0.014) in which, across all treatment phases, the

Discussion

This prospective study is the largest to date (and to our knowledge) assessing potential mechanisms of GER-related asthma using state-of-the-art esophageal and pulmonary methodology. We found that intraesophageal acid is associated with an impairment of PEF in all four groups of subjects, including NC.

Our results agree with a recent study by Wright et al9 in which intraesophageal acid infusions in 136 patients produced a decrease in FEV1 independent of the presence of pulmonary symptoms. This

ACKNOWLEDGMENTS

The authors thank Dr. William C. Bailey for reviewing an early version of this manuscript, Dr. Andrea Miksa who was involved during the planning stages, Dr. Arthur E. Euler of Glaxo Inc for his intellectual and financial support, and Ms. Cynthia Tate for her invaluable assistance in editing this manuscript.

References (33)

  • KjellénG et al.

    Oesophageal function in asthmatics.

    Eur J Respir Dis

    (1981)
  • SontagSJ et al.

    Prevalence of esophagitis in asthmatics.

    Gut

    (1992)
  • OslerWB
  • MansfieldLE et al.

    Gastroesophageal reflux and asthma: a possible reflex mechanism.

    Ann Allergy

    (1978)
  • MansfieldLE et al.

    The role of the vagus nerve in airway narrowing caused by intraesophageal hydrochloric acid provocation and esophageal distention.

    Ann Allergy

    (1981)
  • TanWC et al.

    Effects of spontaneous and simulated gastroesophageal reflux on sleeping asthmatics.

    Am Rev Respir Dis

    (1990)
  • Cited by (0)

    Supported in part by Glaxo, Inc.; NIH Physician Scientist Award, National Heart Lung Blood Institute, grant Kll-ML02195 (Dr. Harding); and National Institute of Digestive Disease and Kidney Disorder, grant RO1-DK40490-OIAI (Drs. Richter and Bradley).

    Presented at Digestive Disease Week, American Gastroenterological Association, May 11, 1992, San Francisco.

    View full text